I have a bunch of sites, and I've experimented with various options. (Example of one site with FB comments on: http://www.hn-books.com/Books/Slaughterhouse-Five.htm ) I've also tried LiveFyre comments and a few other systems.
If there's a benefit to FB commenting by providing more engagement, I'm not seeing it. I love the LiveFyre system, but I'm not seeing a lot of engagement there, either.
My opinion is that any little thing you do to make commenting harder by even a tiny amount has a huge impact on participation. To make matters worse, you're giving up sometimes valuable feedback and participation content to Facebook, which just monetizes it instead of you.
Maybe there's a way to make it pay off. If so, I'd like to hear it.
I think a fair bit of it depends on your needs for moderation, and what you're comparing to.
When you say you're not seeing a lot of engagement with FB/Livefyre, were those sites seeing engagement before with a worse commenting system?
We switched ForeignPolicy.com over to livefyre from the Drupal built-in system and saw a big increase in participation, both in average comments per article and the number of multi-message 'conversations' that people were having in the comments section. That said, we already have an engaged audience, and a big chunk of the benefit may have been new moderation tools that let us reduce spam/trolls.
I don't think that any system will create engagement out of thin air, except in the rare case of a site with a rabid fan base and no commenting/forum system, but i'd argue that systems like disqus and livefyre make people more likely to jump in because they don't need to create an account with you.
If there's a benefit to FB commenting by providing more engagement, I'm not seeing it. I love the LiveFyre system, but I'm not seeing a lot of engagement there, either.
My opinion is that any little thing you do to make commenting harder by even a tiny amount has a huge impact on participation. To make matters worse, you're giving up sometimes valuable feedback and participation content to Facebook, which just monetizes it instead of you.
Maybe there's a way to make it pay off. If so, I'd like to hear it.